1984 Cutlass AC questions

[Carl1984Gbody]

Good day everyone. New to the forum, looks like a lot of great info here. I have an 84 cutlass I've had for about a year. Put a 403 in it and wanted to get AC running, so when i put the motor in, I put a new condenser, ac compressor and replaced all the seals.

Held a vacuum, so went ahead and put 2 cans of 12 in it and the compressor will not come on. I used original oil for the system, got to love rockauto, they have everything. So some questions:

Where is the fuse for the ac system?
Relay location?

May try a new compressor connection, mine looks a little tattered, someone put electrical tape around it. Probably order a new one from rockauto.

Guess that will get me started.

Thank you.

 

[oldsofb]

The connector would come from the factory with the black tape. Do you have gauges on the system? Two cans may not be enough to kick the comp on. Check your voltage like you plan to. If you still have the sticker on the ac box it will tell you the system capacity. I have a chart that says it would be 52oz of freon and 8oz of oil.
Assuming you put in 2 12oz cans that means you're 28oz short (or 2.3 cans). If your elect checks out try a third can and see if it kicks on. Report back if that didn't work.

Good luck,
Hutch

 

[Texas82GP]

Back in the mid 90's I overhauled everything in the engine compartment on an 84 Cutlass Brougham. When I took it apart the A/C worked. It was still an R12 system. I left the compressor hooked up while the engine was out to preserve the charge. When I put everything back together, the A/C compressor would not run. I initially thought the system must have leaked down. When I got a friend to put some gauges on it, they said otherwise. I wasn't as familiar with working on A/C back then so I had to have help. We ended up jumping across the connector for the low pressure switch and the compressor started running and the line to the accumulator and evaporator immediately got cold. We removed the jumper and plugged the connector back onto the low pressure switch and the system started running normally. Evidently the low pressure switch was hung up. I don't think you have quite enough charge in your system but it should try to run. Maybe you have the same problem with a hung up switch. Thought I would post this as a possibility. Hope it helps. Please come back and let us know how it turns out. Also, welcome to the site from Houston. Consider posting an introduction thread in the new users section and tell us some more about your car and yourself. We like new users to introduce themselves and we love to see pics of user's cars.

 

[airboatgreg]

Welcome from SW Georgia.
Fuse in fuse block under dash
You need more Dichlorodifluoromethane for sure.
Jump low pressure switch as said before and see if compressor comes on. Be careful replacing connector to compressor as there is a clamping diode installed there. The technical term is a little black thingy between the terminals that needs to be there. See what happens and let us know brother

 

[Carl1984Gbody]

WOW thank you for all the replies, will def try another can see what happens. Could I trouble you to dumb it down for me, lol, how do I exactly jump the low pressure switch? I had guages on it, actually bought an original set of 12 gauges for it, sucked the two cans right away, so third can may do it. When it cools down, have to try that.

Will def post in the newby thread, just have to find it, lol. New to navigating here.

Will check for the diode as well.

I will have to look harder for the fuse, some of the lettering is kind of faded. Didn't seem like that many fuses on the drivers side, thought there may be another fuse box, will check again.

Thank you again for all the quick replies.

 

[Texas82GP]

WOW thank you for all the replies, will def try another can see what happens. Could I trouble you to dumb it down for me, lol, how do I exactly jump the low pressure switch? I had guages on it, actually bought an original set of 12 gauges for it, sucked the two cans right away, so third can may do it. When it cools down, have to try that.

Will def post in the newby thread, just have to find it, lol. New to navigating here.

Will check for the diode as well.

I will have to look harder for the fuse, some of the lettering is kind of faded. Didn't seem like that many fuses on the drivers side, thought there may be another fuse box, will check again.

Thank you again for all the quick replies.

You are actually bypassing the switch by jumping across the connector. Remove the connector from the switch and jump from terminal to terminal of the connector with a conductor, like a paper clip bent in the shape of a U. You are essentially bypassing the low pressure switch and 'hot wiring' the compressor to run. The control in the car has to be set to A/C and you have to have +12V at one side of the connector (ruling out some electrical problem preventing voltage from getting to the low pressure switch. When you hot wire the low pressure connector, have the gauges on it and watch the low side. If it approaches 0, pull the jumper and let the pressures equalize. If it approaches 0, there is not enough charge. Post up with any further questions.

 

[Carl1984Gbody]

You are actually bypassing the switch by jumping across the connector. Remove the connector from the switch and jump from terminal to terminal of the connector with a conductor, like a paper clip bent in the shape of a U. You are essentially bypassing the low pressure switch and 'hot wiring' the compressor to run. The control in the car has to be set to A/C and you have to have +12V at one side of the connector (ruling out some electrical problem preventing voltage from getting to the low pressure switch. When you hot wire the low pressure connector, have the gauges on it and watch the low side. If it approaches 0, pull the jumper and let the pressures equalize. If it approaches 0, there is not enough charge. Post up with any further questions.

Ok cool, thank you for the reply, makes sense. I will give that a try when I get back in town and motivated to get my *ss back on it, lol. Appreciate it.

 

[airboatgreg]

Depending on the can you may need up to 5 cans. The may be a sticker near the blower motor telling you the capacity. As I recall 3 and 3/4 lbs of refrigerant.

 

[Carl1984Gbody]

Depending on the can you may need up to 5 cans. The may be a sticker near the blower motor telling you the capacity. As I recall 3 and 3/4 lbs of refrigerant.

Interesting how diff vehicles take different amounts. The 84 is listed as 52oz, I will be happy when I hear that comp click on, lol. Thanks all for the responses.

 

[roger1]

It's good to buy 12 and 14oz cans when you buy R12 if you can.
If you only have 12oz cans, it's going to take 5 cans to get 52oz and you will have to weigh the last can during filling to only add 4 oz from it. You will most likely have to waste the rest.
Two 12oz cans and two 14oz cans gets you 52oz and no weighing needed.

Always best to jumper the low pressure switch during the fill process. If it's hot outside use a box fan to blow into the radiator a few feet out.
Run your engine at 1200 to 1500 rpm and set the inside controls to max and fan on high.
Put thermometer in the center vent and hope you can get around 40 degrees depending on the outside temp. If it's not a hot day, it is possible you could freeze your evaporator during the charge. Running the fan on high speed will help keep that from happening. In normal operation, the low-side switch prevents freeze up. A freeze up of the evaporator doesn't hurt anything in the system but the air will blow warm out the vents until it thaws.

Always good to use a infrared laser temperature gun and shoot the temperature of the compressor case. If it runs over 140, you should add more oil. Once the system is charged, you can get an inexpensive injector to be able to add oil to a charged system. Don't add any more than 1/2oz at a time and make sure you use oil for R12 an not R134a.